#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
    int n, level = 0, count = 0;
    char dir;
    bool inValley = false;
    cin >> n;
    for (int i = 0; i < n; i++){
        cin >> dir;
        
        if(dir == 'U'){
            level++;
        }else{
            level--;
        }
        
        if(!inValley && level < 0){
            inValley = true;
        }else if(inValley && level >= 0){
            inValley = false;
            count++;
        }
    }
    cout << count;
    return 0;
}